Apparatus and Method for Processing an Audio Signal Using Linear Prediction

1. A method of decoding an audio signal, comprising: receiving an audio data frame having at least one channel, the channel being subdivided into a plurality of blocks, at least two of the blocks being capable of different lengths; obtaining indicator information indicating whether determining of a first prediction order for each block is allowed; obtaining a second prediction order if the indicator information indicates that determining of the first prediction order for each block is not allowed, the second prediction order being applied to all of the plurality of blocks; determining the first prediction order for each block from the audio signal if the indicator information indicates that determining of the first prediction order for each block is allowed, the first prediction order for each block having been determined according to the second prediction order and a length of the block; and decoding each block using the determined first prediction order for each block or the obtained second prediction order for the plurality of blocks.

2. The method of claim 1 , wherein the first prediction order is determined by; obtaining a global prediction order from the audio signal; obtaining a local prediction order from the audio signal; and determining a minimum one of the global prediction order and the local prediction order as the first prediction order.

3. The method of claim 2 , wherein the global prediction order received from audio signal is equal to, ceil(log2(permitted maximum prediction order +1), wherein the permitted maximum prediction order is the second prediction order.

4. The method of claim 2 , wherein the local prediction order received from audio signal is equal to, max(ceil(log2((Nb>>3)−1)), 1), wherein Nb is the length of the block.

5. A method of processing an audio signal, comprising: subdividing a channel in a frame of the audio signal into a plurality of blocks, at least two of the blocks being capable of different lengths; generating indicator information indicating whether determining of a first prediction order for each block is allowed; determining a second prediction order for the plurality of blocks if the indicator information indicates that determining of the first prediction order for each block is not allowed, the second prediction order being applied to all of the plurality of blocks; determining the first prediction order for each block if the indicator information indicates that determining of the first prediction order for each block is allowed, the first prediction order for each block being determined according to the second prediction order and a length of the block.

6. The method of claim 5 , wherein the determining the first prediction order step comprises: determining a global prediction order based on the second prediction order; determining a local prediction order based on the length of the block; and selecting a minimum one of the global prediction order and the local prediction order as the first prediction order.

7. The method of claim 6 , wherein the determining a global prediction order step determines the global prediction order as equal to, ceil(log2(permitted maximum prediction order +1), wherein the permitted maximum prediction order is the second prediction order.

8. The method of claim 6 , wherein the determining a local prediction order step determines the local prediction order as equal to, max(ceil(log2((Nb>>3)−1)), 1), wherein Nb is the length of the block.

9. The method of claim 5 , wherein the subdividing step subdivides the channel according to a subdivision hierarchy, the subdivision hierarchy has more than one level, and each level is associated with a different block length.

10. The method of claim 9 , wherein a superordinate level of the subdivision hierarchy is associated with a block length double a block length associated with a subordinate level.

11. An apparatus for decoding an audio signal, comprising: a decoder configured to receive an audio data frame having at least one channel, the channel being subdivided into a plurality of blocks, at least two of the blocks being capable of different lengths, the decoder configured to obtain indicator information indicating whether determining of a first prediction order for each block is allowed, the decoder configured to obtain a second prediction order if the indicator information indicates that determining of the first prediction order for each block is not allowed, the second prediction order being applied to all of the plurality of blocks, the decoder configured to determine the first prediction order for each block from the audio signal if the indicator information indicates that determining of the first prediction order for each block is allowed, the first prediction order for each block having been determined according to the second prediction order and a length of the block, and the decoder configured to decode each block using the determined first prediction order for each block or the obtained second prediction order for the plurality of blocks.

12. The apparatus of claim 11 , the decoder further comprising: a predictor configured to predict current data samples in the channel based on previous data samples, a number of the previous data samples used in the predictor being equal to one of the first prediction order and the second prediction order; and an adder configured to add a residual of the current data samples received from the audio signal to the predicted data samples.

13. The apparatus of claim 11 , wherein the first prediction order is determined by; obtaining a global prediction order from the audio signal; obtaining a local prediction order from the audio signal; and determining a minimum one of the global prediction order and the local prediction order as the first prediction order.

14. The apparatus of claim 13 , wherein the global prediction order received from audio signal is equal to, ceil(log2(permitted maximum prediction order +1), wherein the permitted maximum prediction order is the second prediction order.

15. The apparatus of claim 13 , wherein the local prediction order received from audio signal is equal to, max(ceil(log2((Nb>>3)−1)), 1), wherein Nb is the length of the block.

16. An apparatus for encoding an audio signal, comprising: an encoder configured to subdivide at least one channel in a frame of the audio signal into a plurality of blocks, at least two of the blocks being capable of different lengths, the encoder configured to generate indicator information indicating whether determining of a first prediction order for each block is allowed; the encoder configured to determine a second prediction order for the plurality of blocks and to encode the plurality of blocks to produce a compressed bitstream based on the second prediction order if the indicator information indicates that determining of the first prediction order for each block is not allowed, the second prediction being to all of the plurality of blocks; the encoder configured to determine the first prediction order for each block and to encode the plurality of blocks to produce a compressed bitstream based on the first prediction order if determining of the first prediction order for each block is allowed, the first prediction order for each block being determined according to the second prediction order and a length of the block.

17. The apparatus of claim 16 , further comprising: a predictor configured to predict current data samples in the channel based on previous data samples, a number of the previous data samples used in the predictor being equal to one of the first prediction order and the second prediction order; and a subtracter configured to calculate a prediction residual of the block using an original value and the predicted data samples.

18. The apparatus of claim 16 , wherein the first prediction order is determined by: determining a global prediction order based on the prediction order; determining a local prediction order based on the length of the block; and selecting a minimum one of the global prediction order and the local prediction order as the first prediction order.

19. The apparatus of claim 18 , wherein the determining a global prediction order step determines the global prediction order as equal to, ceil(log2(permitted maximum prediction order +1), wherein the permitted maximum prediction order is the second prediction order.

20. The apparatus of claim 18 , wherein the determining a local prediction order step determines the local prediction order as equal to, max(ceil(log2((Nb>>3)−1)), 1), wherein Nb is the length of the block.